diff --git a/sw/airborne/arch/lpc21/mcu_periph/pwm_input_arch.c b/sw/airborne/arch/lpc21/mcu_periph/pwm_input_arch.c
index 4147a51aaf..15944be5d3 100644
--- a/sw/airborne/arch/lpc21/mcu_periph/pwm_input_arch.c
+++ b/sw/airborne/arch/lpc21/mcu_periph/pwm_input_arch.c
@@ -144,18 +144,25 @@ void pwm_input_isr2(void)
     t_fall = T0CR0;
     T0CCR |= TCCR_CR0_R;
     T0CCR &= ~TCCR_CR0_F;
-#if USE_PWM_INPUT2 == PWM_PULSE_TYPE_ACTIVE_LOW
-#else
-    pwm_input_duration[1] = t_fall - t_rise;
-    pwm_input_valid[1] = TRUE;
+#if USE_PWM_INPUT2 == PWM_PULSE_TYPE_ACTIVE_HIGH
+    pwm_input_duty_tics[1] = t_fall - t_rise;
+    pwm_input_duty_valid[1] = TRUE;
+#elif USE_PWM_INPUT2 == PWM_PULSE_TYPE_ACTIVE_LOW
+    pwm_input_period_tics[1] = t_fall - t_oldfall;
+    pwm_input_period_valid[1] = TRUE;
+    t_oldfall = t_fall;
 #endif //ACTIVE_HIGH
   } else if (T0CCR & TCCR_CR0_R) {
     t_rise = T0CR0;
     T0CCR |= TCCR_CR0_F;
     T0CCR &= ~TCCR_CR0_R;
 #if USE_PWM_INPUT2 == PWM_PULSE_TYPE_ACTIVE_LOW
-    pwm_input_duration[1] = t_rise - t_fall;
-    pwm_input_valid[1] = TRUE;
+    pwm_input_duty_tics[1] = t_rise - t_fall;
+    pwm_input_duty_valid[1] = TRUE;
+#elif USE_PWM_INPUT2 == PWM_PULSE_TYPE_ACTIVE_HIGH
+    pwm_input_period_tics[1] = t_rise - t_oldrise;
+    pwm_input_period_valid[1] = TRUE;
+    t_oldrise = t_rise;
 #endif //ACTIVE_LOW
   }
 }